39510-74-2Relevant articles and documents
Zinc acetate-mediated regioselective N-acylation of 1,3-disubstituted selenoureas
Li, Xue,Gan, Bin,Peng, Zhixiang,Mi, Zhisheng,Xie, Yuanyuan
, p. 251 - 254 (2018/06/27)
N-acetylureas were synthesised regioselectively from 1,3-disubstituted selenoureas and zinc acetate. Regioselectivity was dependent on the pKa of the amine attached to the selenourea and occurred towards the amine with the lower pKa. The approach provided a simple, mild and efficient way to construct various N-acetylureas regioselectively in moderate to good yields (53-88%). A plausible mechanism was proposed for the formation of N-acetylureas.
Hypervalent iodine(III)-mediated regioselective N-acylation of 1,3-disubstituted thioureas
Singh,Ghosh, Harisadhan,Murru, Siva,Patel, Bhisma K.
, p. 2924 - 2927 (2008/09/19)
(Chemical Equation Presented) Reaction of asymmetrical 1,3-disubstituted thioureas with diacetoxyiodobenzene (DIB) produces regioselectively N-acetylurea in shorter time. Regioselectivity is dependent on the pKa's of the amine attached to the t
Oxidative rearrangement and cyclisation of N-substituted amidines using iodine(III) reagents and the influence of leaving group on mode of reaction
Ramsden, Christopher A.,Rose, Helen L.
, p. 2319 - 2327 (2007/10/03)
The products of reaction of N-substituted amidines 5 with hypervalent iodine reagents such as (diacetoxyiodo)benzene (DAIB), bis(trifluoroacetoxy)iodobenzene (BFIB) and [methoxy(tosyloxy)-iodo]benzene (MTIB) are determined by the reagent, the amidine substituents and the reaction temperature. C-Alkyl-N-arylamidines 5a-d cyclise in high yield giving benzimidazoles 6 but C,N-dialkyl- and C,N-diaryl-amidines 5e-l rearrange to give products derived from an intermediate carbodiimide. Use of N2-phenylfuran-2-carboximidamide 5j leads to N-(2-furyl)acetamide 15 in good yield, illustrating a convenient route to stable derivatives of highly unstable 2-aminofuran. The rearrangement of C,N-diarylamidines on reaction with DAIB contrasts with the observed formation of benzimidazole when the same precursors are treated with lead tetraacetate (LTA). Evidence is presented to support the view that the mode of reaction is determined by the nature of the leaving group in an imide intermediate 19: very good leaving groups [e.g. PhI, N2, AgCl and PhSO2O- (aq.)] appear to favour rearrangement whereas poorer leaving groups [e.g. Cl-, Me2S, Me3N and PhSO2O- (non-aq.)] favour cyclo-α-elimination.